Permanent
by GhostInTheBAU
Summary: One of Stiles' worst fears comes true, and in his shock he shuts himself off from the rest of the pack. But when a certain moody alpha shows up at his house, worried and a bit annoyed, he breaks down, clinging to the wolf for solace and comfort. The sort of comfort, it seems, only Derek can provide.
1. Wrong

_So, this is my first foray into writing for Teen Wolf. I usually play in the Criminal Minds sandbox, but I finally discovered this show a few months ago and I'm a bit obsessed with Sterek now. I just can't help it. I have no regrets._

 _This fic was inspired by a Teen Wolf fan video on youtube to the song **Permanent** by David Cook. I would highly recommend giving it a watch, but fair warning, it's sad. Really, really sad. I can assure you that this story ends much happier than that one._

 _**I'm just gonna go ahead and list all the warnings I posted on another site here to cover all the bases** : Porn with Plot, Porn with Feelings, Underage, Sick Stiles, Frontotemporal Dementia, Stilinski Family Feels, No Nogitsune, Angst, Comfort, Stiles has Panic Attacks, Mildly Dubious Consent, because Stiles is seventeen and sort of emotionally vulnerable, but he knows what he wants, Loss of Virginity, Blow Jobs, Barebacking, Alpha Derek, Top Derek Hale, Bottom Stiles Stilinski, Scenting, Anal Fingering, Anal Sex, Gentle Sex, Comeplay, NSFW, Werewolf Pain-Relief Magic, Caring Derek, Derek is not a Failwolf, his wolf does get a little possessive though, Getting Together, Hopeful Ending_

* * *

Chapter One

Wrong

.

 _ **Is this the moment where I look you in the eye?  
Forgive my broken promise that you'll never see me cry.  
And everything, it will surely change even if I tell you I won't go away today. **_

.

"Frontotemporal dementia."

Those two words echo in Stiles' mind, a cold snap stealing his breath and leaving him numb.

This is wrong. So wrong.

It has to be wrong.

He's in shock.

"Are...are you sure?" he hears his dad ask beside him, the man's voice hoarse and tired.

You see, this whole thing started with a tremor in his hand. It was a tiny little thing, really, barely even detectable. A blip on the radar of worrisome things that happen in and around Beacon Hills. At the time he'd merely chalked it up to too much Adderall, especially since everyone knows he has a bad habit of abusing the dosage amounts in order to fit his own needs.

But then he'd started having trouble sleeping—or rather, staying asleep. He'd woken up in a cold sweat nearly every single night for the past two weeks, a scream in his throat and the lingering remnants of nightmares ghosting through his mind, haunting him well into the dawn.

Of course, the lack of sleep had then led to an inability to concentrate on his school work; and in turn, he'd also had no desire to spend time with his friends.

He doesn't even seem to care about his dad's diet anymore—which, okay, _major_ red flag right there.

He's always irritable, and tired, and jittery; and he can't find the right words to express how he's feeling half the time. They get jumbled up in his mind; and it's all so _infuriating_ , and exhausting, and he just...feels lost in his own skin.

The tipping point, however, came when he'd thought he'd seen a monster in his room—an honest to god, flesh and blood creature of the fucking night—which, again, Beacon Hills, so...totally possible, right?

Right.

Sure.

Definitely.

 _Wrong._

It hadn't been a monster. It hadn't been anything at all.

He'd been alone in his room, safe and sound, and he'd had a hallucination.

That's when his dad had decided to bring him to the hospital for tests; and now they were sitting across from his doctor, a specialist, a _neurologist._ Actually, it was the same neurologist who'd diagnosed his mother, ironically.

Stiles can't remember the guy's name, but he tries not to dwell on that troubling fact too much. That's the sort of thinking that inevitably leads to falling into an abyss of worry and fear—a void, dark and cold and massive—and absolutely terrifying unlike anything he's ever faced before.

Werewolves, kanimas, geriatric fucking hunters...you name it, none of them hold a candle to what he's facing now.

He closes his eyes and tries not to fidget as he wrings his hands together, nails digging into his palms, clammy with sweat. He knows he's on the verge of hyperventilating, can feel his eyes stinging and his body trying to shut down. The chair he's sitting in is hard and unforgiving beneath him.

"Yes, Mr. Stilinski, I'm fairly certain," the doctor answers, his tone soft, expression calm and collected—kind of soothing, in its own way. Dude's probably used to giving horrible news to people on the daily, breaking their hearts and shattering their lives, killing all their hopes and dreams just like a goddamned Disney villain. It has to be a prerequisite or something, in his line of work. Pausing, he pulls Stiles' brain scans and MRI images up on his computer before turning the screen around to face them. "You see this?" he points the end of his pen to a spot on the scan, waiting patiently for both Stiles and his father to focus on the image, "Both those spots are showing signs of atrophy."

Again, he feels numb, like he's not really there. It's like he's watching a movie, one of those _Lifetime_ ones—a real tear-jerker—and this is all happening to someone else, some other poor high school kid who just can't seem to catch a break.

"Your symptoms are consistent with the MRI results, Stiles," the neurologist continues, addressing him directly, "I know this isn't what you want to hear—"

Stiles scoffs at that. He just can't fucking help it. His dad's hand comes up to latch onto both of his, holding tight. Painfully tight.

"—but, there are new therapies we can try, and some very promising trials we should look into. I'll get you the information."

"How—" his dad chokes on the words he's trying to say, clears his throat, holds his hand tighter. This has to be killing him. "How long are we talking about here, doc?"

The doctor hesitates before he answers. It's just a fraction of a second, but Stiles notices.

"The length of progression varies from case to case, as I'm sure you're aware, but...the median life expectancy is eight years from the onset of symptoms. I can't give a more definitive answer. It may be more, may be less. Every patient is different."

No shit. His mother didn't have eight years, why the hell should he be any different?

He shouldn't.

He's not.

He's not different.

No, he's just like her. He's going to die just like his mother did, and his dad's gonna have to watch as it happens. His dad's going to have to suffer through that shit storm of pain all over again. How fair is that?

It's _so_ not fair.

It's wrong.

It's a fucking _nightmare—_ one they've both lived through before; and now fate has decided that Stiles Stilinski's luck has finally run out.

He's going to die.

Oh god, he's gonna _die._

The revelation hits him like a ton of bricks.

He's gonna die, and suddenly he can't _breathe_ , can barely see past the black spots dancing around in his vision.

Something's wrong with him.

So wrong.

There's a tightness curling icy tendrils around his chest, and a pressure, like a fucking elephant sitting on his ribs, and it _hurts._ It fucking hurts, and it's too much.

It's all too much, and he can't deal right now. He can't handle this. How is he supposed to handle this?

He tries to gulp in air but he can't fucking do that either. His throat's closed up tight, heart pounding out an erratic rhythm in his ears, the roar of it mingling with the buzzing in his head, and he can't stop _shaking._ Can't move past the sudden nausea flooding his mouth with waves of salt and saliva, bile creeping up his esophagus, burning through him.

He doesn't wanna die.

He doesn't wanna leave his dad, or Scott. Lydia or Allison. Or even Derek fucking Hale.

He wants to be here for all the things he's gonna miss.

It's not fucking fair!

He hears his dad's voice, but it sounds far away. Too far.

He wraps his arms around his middle, trying desperately to hold himself together even though it feels like an impossible task. He's shattering into a million jagged pieces and he can't catch them all.

"You're gonna be okay, son." A warm hand cups the back of his neck, pulls him into a firm chest, arms wrapping securely around him, holding him close. He can smell his dad's aftershave, can hear the rapid beat of his heart and the tremor in his voice. His dad's scared, and something about that just about breaks Stiles. "You hear me? No matter what happens, I'm...I'm gonna be with you, and it's all gonna be okay."

"No no no, it's not. It's not. Daddy..." his voice cracks, breath hitching in his throat, cutting off his words with a sob, and then he's just full out _crying_. He can't help it. His eyes are burning as hot tears stream down his face. Everything hurts, and he's so scared. He's so, _so_ fucking scared. He's that frightened little eight year old boy again, alone in the hospital, crying out for his daddy as he watches a hateful disease kill his mother right before his very eyes.

The same disease that's gonna kill him.

He's dizzy, and hot, and everything still hurts.

And fuck, he can't _breathe!_

"I've got you." Strong hands cradle either side of his face then, pulling him away just enough for him to meet his dad's watery gaze. "Stiles, please—I need you to calm down for me. Try to take a deep breath, okay? With me..." He watches through blurred vision as his dad breathes in and holds it, then let's the air back out slowly. "Come on, kiddo. Just try. Deep breath in..."

He gives a jerky nod, studying his dad's face like breathing is some sort of nuclear fucking science instead of a simple biological drive. It shouldn't be this hard. Still, he tries, relaxing his shoulders, swallowing down the lump in his throat and taking a deep inhale in time with his dad's. Instantly his body sags with relief as oxygen rushes in, and he takes another breath, then another, and another. He keeps going until his head's less fuzzy and he's not seeing spots anymore.

"There you go, kid. There you go...you're doing great. Keep it up, now." The praise is given on the tail end of a shaky exhale, as though his dad didn't truly believe he was gonna be able to pull it off or something. "Just breathe, and we'll get through this."

 _We'll get through this._

Get through what, exactly?

The panic attack? The illness? _Dying?_

Stiles doesn't really know what they're supposed to get through.

"You're okay, Stiles. We're..." there's a pause, and he's being pulled back into a fierce hug, "I've got you, son, and we're gonna be okay."

"Yeah," he rasps, wrapping his arms around his dad and clinging to him like a lifeline, the only thing keeping him afloat, "Yeah, okay."

He doesn't believe it, though.

He doesn't think anything's ever gonna be okay again.

* * *

His dad has to work the late shift, but they have a few hours before he needs to leave so they go home and spend the evening watching _The Avengers_ and eating pizza. Meat lovers, extra bacon because...well, why the hell not? He's not sure if his apathy is due to the stress of the day or his illness at this point, and he doesn't really care, which he guesses is sort of fitting. Irony and all that. He doesn't actually end up eating much, though, just picks at it with his fingers; but the little bit of joy he can see when his dad takes a bite is good enough for him.

Right as the Hulk is slamming Loki around in the Avenger's Tower he hears his phone chime with a new text, so he picks it up and unlocks it, reading the message while he pops a piece of pepperoni in his mouth.

 **[Received: 6:46pm]**  
 _Rogue omega in the Preserve. Get to the loft asap. - Derek_

Not long ago Stiles would have jumped at the chance to get out into the thick of another Beacon Hills catastrophe waiting to happen, but now he just wants to pretend that nothing exists outside his house. He has bigger monsters to deal with, and he can't handle anything else so he chooses to go the way of total avoidance, ignoring the message altogether and bringing his attention fully back to the movie. The others, the ones with _actual_ supernatural abilities, can deal with the werewolf. He'll just sit here and try not to fall apart.

After a while, though, when he doesn't respond to Derek, the texts grow more persistent, and Scott seems to get in on the action as well.

 **[Received: 7:28 pm]**  
 _Stiles, where are you? - Derek_

 **[Received: 7:55 pm]**  
 _Get here. Now. - Derek_

 **[Received: 8:11 pm]**  
 _Dude, Derek's flipping. Where r u? - Scotty_

 **[Received: 8:24 pm]**  
 _Wanted 2 let u know everything's cool. Guy was just passing thru. What happened w/ u? Hope ur ok. Call me! - Scotty_

 **[Received: 8:29 pm]**  
 _If you're not dead, I'm gonna kill you. - Derek_

Finally, his dad gives him a questioning glare and Stiles huffs in annoyance, making a big show out of turning his phone to silent before shoving it in his pocket.

The funny thing is, if he were being totally honest with himself, there was a time when Stiles would have loved to receive so much attention from the alpha of the Hale pack—although, he could definitely do without the homicidal undertones. Hell, he'd been holding a torch for Derek Hale since the first time they'd met out in the Preserve. He'd spent hours pining over him and his ridiculously stubbled jaw, overly judgmental eyebrows, gorgeous green eyes, and rock hard abs. Oh, and the leather...let's not forget about the leather.

Of course, sometimes it was hard to see past the whole _throw-you-up-against-a-wall_ or _slam-your-head-into-a-steering-wheel_ persona the guy had going on.

Seriously, dude could benefit from some fucking therapy.

Or a chill pill.

Or maybe both.

But there were other times when Derek would surprise him. He'd let Stiles see a different side of him, a softer side, one that most people didn't get to see—it was a side that made him think his feeling for the werewolf might possibly be reciprocated. Just little touches and looks that no one else ever noticed. A brush of fingers that seemed to linger just a few seconds longer than necessary. A private smile hidden in shadows that felt like it was just for him. It was all unspoken, but it was there. Stiles knew it was there, and he had no doubt that _something_ was happening between them. He'd never said anything, though, because he also didn't have a death wish.

Too bad all that pining and sexually charged tension is gonna go to waste now.

Stiles has an expiration date looming above his head, and it's all too little, too late.

After the movie ends, he says goodnight to his dad and makes his way up the stairs to his room, changing into a pair of flannel sleep pants and an old t-shirt; and when his phone rings with an actual incoming call, flashing _'Derek'_ across the screen, he doesn't answer it.

He just turns it off and tries to go to sleep.

* * *

When Derek arrives at the Stilinski residence and sees Stiles' Jeep parked in the driveway and a light on in his bedroom window he's livid, to say the least. Stiles hadn't returned any of his or Scott's texts throughout the night, or answered any of his numerous phone calls; and eventually he'd had enough, deciding to just drive over and check on the kid in person, questions and worse case scenarios running through his mind the entire time.

Why hadn't Stiles answered his phone?

Was something or someone keeping him from responding?

Was he in danger?

Had something happened to the Sheriff?

All those questions had vanished, new ones taking their place the moment he'd realized Stiles was indeed home, and apparently safe and sound.

Derek knows Stiles, or at least he likes to think he does, and it's not like him to ignore his friends, especially if there's an edge of danger involved. The kid's survival instincts are shit, in all honesty, so he's usually the first one running into the fray, getting tangled up in every supernatural mess Beacon Hills has to offer.

That's how the two of them had met, in fact. Stiles and Scott had been looking for Scott's inhaler, which they'd lost after Stiles had dragged Scott out into the Preserve in the middle of the night, in search of a dead body.

His _sister's_ dead body.

Admittedly, it hadn't been the best first impression, for either of them.

Derek's grown rather fond of him over the last year, though, relying on him more than he'd care to admit. Stiles has helped save his life on more than one occasion. He's part of the pack, and because of that Derek had thought he would've jumped at the chance to get out there and hunt down a rogue were.

But Stiles hadn't jumped, he'd avoided.

Something's wrong, Derek can feel it in his bones, and he needs to figure out what it is.

He wants answers, and he's going to get them.

When he leaps up onto the roof and peers through the window, he sees Stiles lying on his bed, facing the wall. Carefully and quietly, he opens the window and climbs inside, ignoring how utterly creepy that really is as the teen begins to stir. To his credit, he waits until Stiles rolls over and looks in his general direction before he completely loses his shit, yelling, "Where the hell have you been? And why haven't you answered any of the pack's calls?"

Stiles sits up, closing his eyes and rubbing at the back of his neck, the light from the lamp on the bedside table casting a golden glow across his pale skin. He lets out a long, heaving sigh like he's not even fucking surprised Derek's standing in the middle of his bedroom, then glances back up, his eyes blood shot and red-rimmed. "Well okay, then...nice to fuckin' see you too," he mutters, his tone biting, "I'm so sorry I wasn't at your beck and call, but believe it or not, _Derek_ , there's things that go on around here that don't actually involve you. It's a novel concept, I know."

Derek immediately bristles, hearing the uptick in Stiles' heart rate, how it spikes; and he smells the sour tinge of anxiety, grief, anger and exhaustion wafting off of him. The combination of all those emotions mixing together is thick, filling the space between them and making him nauseous. He doesn't know what's going on, but he's pretty sure it's nothing good.

Worse than some rogue werewolf on the loose, it would seem.

"What happened?" he asks, trying to calm his voice.

"Why the fuck would you care?" Stiles spits back, but as soon as the words are out Derek can see the regret etching itself onto his features—the slight crease of his brow, the grimace sliding across his lips, the tense set of his body, the clench of his jaw. And then he just...deflates, slumping against the headboard and rubbing his hands through his disheveled, sleep-mussed hair. "Sorry," he lets out another huff of air, tired, "I'm...sorry. Look, I went to the doctor, okay? I've been having some...trouble lately. You know, um, with headaches and, and concentration. And some other things."

"What's wrong with you?" Derek doesn't even stop to think about how insensitive the question is. All he'd heard was _doctor_ and _trouble_ and _other things_ , and he just had to know.

"It's called frontotemporal dementia," Stiles murmurs, letting out another heavy sigh, staring at his lap, "It's what my mother had. It's what killed her."

"Stiles..." Suddenly he feels like the floor is flying out from under him, his stomach dropping right along with it as a ball of dread coils deep in his chest. There's ice creeping into his veins, but he listens quietly as Stiles continues.

"You know, I did a lot of research, before, while she was sick and stuff; and I saw it in action, so I pretty much know what's coming. I had a front row seat to my future...I know what's gonna happen to me. It's degenerative, so I'll just keep getting worse and worse. Parts of my brain are going to shrink, the parts that control who I am—my, my personality, and the way I act, even how I fucking walk...how I _breathe_ —it's, it's all going to _deteriorate._ And then, after all that, do you know what's gonna happen, Derek? Do you know what that _means?"_ He stops, looking directly at Derek as though he wants to punch him square in the fucking face before he moves his gaze away again, down to the floor; and Derek just swallows the lump in his throat, doesn't say anything, "It means I'm gonna die young. Probably from pneumonia or some bullshit." Derek takes a step forward, toward the bed, his heart racing; but he stops when Stiles looks back up at him, eyes misty and glistening. "There's no cure," a single tear rolls down his cheek, and Derek's beside him in an instant, sitting on the edge of the bed and pulling him into a hug before he even knows what he's doing, "Derek, there's...there's no cure."

All he can think as he's holding Stiles' trembling body is, _No, no, no. Why is this happening? Why him? Please, not him. This is wrong. It has to be a mistake. This is so wrong._ But what he says against Stiles' hair is a strangled, "When? When did you find this out?"

"This afternoon."

And then, hesitant, like he's terrified of the answer, he softly asks, "How long?"

Stiles pulls away and rubs the heels of his hands over his face, scrubbing vigorously. "Um, I dunno. I guess...a couple years, maybe? Fuck, my mom, she—" he bites his upper lip, worrying it between his teeth as his eyes bore a hole into the floor again, "She...didn't have that long."

"God, Stiles. I'm so sorry."

"Yeah," he laughs, but there's absolutely no humor in it at all, "Me too."

Derek doesn't know what else to say or do, what would make Stiles feel better. Probably nothing, honestly. All he does know is that he wants to wrap his arms around him and pull him back into his chest, hold on for dear life, protect him from the world and everything in it; but that's probably not a good option either, since Stiles can't even fucking look at him for more than a few seconds. Besides, what can Derek really do about something like this anyway? How can he make it better? It's not like this is some supernatural creature he can vanquish and be done with. He can't hunt it down, defeat it and save the day.

He can't tell Stiles that everything's going to be okay. He wishes to god that he could, but he can't, because he just doesn't know.

He doesn't know if anything's going to be okay.

In the end, he decides it's probably best if he just leaves.

"I'll go," he murmurs, standing from the bed, "...let you get some rest."

"Derek," Stiles grabs his arm, glancing up at him to reveal tear streaked cheeks, shining in the light, "Stay? Please stay. I, um...I don't think I wanna be alone right now."

He gives the request a wary thought. "What about your dad? If he finds me in here—"

"He won't. He's not here. He's, he's working a late shift tonight, won't be back 'til mid-morning."

"Okay." The answer flows from his lips easier than breathing. He wants to stay. Wants to make sure Stiles is okay—or, well, as okay as he can be.

He squares his jaw, gives a quick nod of resolution, and makes his way over to the desk on the other side of the room, psyching himself up for what's sure to be a long night trying to sleep in a torturous rolling chair.

Before he makes it two steps, however, he hears movement on the bed, the rustle of sheets.

"You don't have to..." Stiles stops, and Derek listens to the uptick in his heartbeat, smells the scent of uncertainty permeating the air, "You can sleep with me, um, if you want." That has him turning around on his heels, giving Stiles a questioning raise of his brows; and Stiles' eyes immediately go big as saucers, mouth gaping, "Not like that! Geeze...I mean, you can lie down here, and just, you know... _sleep."_

Stiles' body language and scent tell a completely different story than his words, but Derek shucks off his jacket just the same before sliding into the bed and pulling the covers up, doing his best to stay as close to the edge as possible. He can feel his own heart picking up speed, thudding anxiously in his chest, the tips of his ears and his cheeks burning from being in such close proximity to someone else.

Someone he's had certain stirrings for.

Someone way too young for him to be having those stirrings for, quite fucking frankly.

He feels Stiles shift beside him, moving closer as a timid hand comes up to rest on his bicep; then there's a soft, barely audible voice, imploring, "Would it be okay if, um, I mean...can you just...hold me?"

He does so without even thinking about it, like his body's on autopilot, moving on its own accord. He raises his arm to make room, and Stiles sidles up next to him, head pillowed on his shoulder and hand fisting into the soft fabric of the Henley he's wearing. He wraps his arms around Stiles and lays his cheek atop his head, his lips brushing against Stiles' hairline as he breathes in deep, closing his eyes and relaxing into the scent.

Gradually Stiles' heart rate and breathing patterns begin to slow, evening out as his body loses some of it's tension; and Derek thinks maybe he fell asleep, so he lets his own eyes close and starts to drift off as well.

Before he knows it, though, he's jolting back to hazy awareness.

"Is this weird?" the voice comes from beneath his chin, melancholy and small, "Um, yeah...this is—it's probably weird, right?"

"Yeah, maybe," he answers honestly, his fingers tracing up and down Stiles' back, the fabric of the shirt he's wearing soft from too many washings, "It's a little weird, but I don't mind."

He really doesn't.

It feels different, having stiles in his arms like this, but it doesn't feel _bad._ It doesn't feel wrong like he'd feared it would. It feels...familiar, comfortable...right. It feels like home. Derek hasn't had a home in so long, and this, right here, holding Stiles, well...it feels exactly like coming home.

Stiles shudders against him, and lets out a strangled sob that seems to go on and on forever, tears quickly soaking through Derek's shirt as long fingers clench tightly to the fabric. "I'm really scared," he whispers, "Der, I'm sorry, but I'm so, so _scared_."

"Shhh, don't apologize," he murmurs, pulling Stiles in closer, soft hair grazing his chin as he drowns in the fear and sorrow filling the room, "I know you're scared, Stiles. I do. I'm...I'm pretty scared, too."

And then the dam breaks, and Stiles breaks right along with it, bawling, full bodied sobs wracking his frame as Derek tightens his grip. He holds on and lets him cry for as long as he needs, his own eyes burning with the threat of unshed tears. Instead of letting them fall, though, he does his best to blink them away, focusing on rubbing soothing circles along Stiles' back while murmuring whispered words of comfort in his ear.

After a while, when the sobs subside and the only sounds left in their wake are sporadic sniffles and trembling breaths, he quietly says, "I could give it to you, you know. The Bite. I _will_ give it to you, if you want me to."

Stiles' breath hitches at that, and there's a beat of silence, then, "Yeah, I know." He doesn't elaborate further, just nuzzles closer into the warmth of Derek's body, and Derek cards his fingers through Stiles' hair.

The Bite will be a subject for another day, he supposes. He's not going to push it, not right now, but he won't let it go either. It's a viable option, one that could save Stiles' life, and it needs to be considered thoroughly.

But for now, there's nothing left for them to do but sleep.

So they sleep.

.

 _ **I know he's living in hell every single day.  
And so I ask, "Oh God, is there some way for me to take his place?"**_

.

* * *

 _I went back and forth over whether to break this up into two chapters or not, but I really felt like this was a natural end to the scene. So, I hope you enjoyed the first chapter! The second chapter will be up soon, and it is very NSFW..._


	2. Right

Chapter Two

Right

.

 _ **And when they say it's all touch and go,  
I wish I could make it go away.**_

.

When Derek wakes up, early morning sunlight is drifting in through the window, casting its rays along the worn hardwood floor while little dust motes float softly through the air, like glitter. He can hear the tick of a clock somewhere in the house, the constant hum of a refrigerator, the passing of a car out on the street. For a moment he's completely forgotten where he is, but then there's movement as the person lying on top of him shifts, and he finds himself staring straight into sleepy hazel eyes—eyes framed by long lashes and a sprinkling of little moles and freckles.

That's when everything comes rushing back to him in stark relief.

He remembers the night before, remembers the anger he'd felt as he'd climbed into Stiles' bedroom window.

Remembers the fear that had taken him over once he'd learned of Stiles' illness, and the desperation in Stiles' voice as he'd asked him to stay the night.

" _Derek, stay? Please stay."_

He remembers falling asleep with Stiles in his arms, holding him close.

Then, abruptly and without warning, he's brought out of his thoughts by a warm set of lips on his, and they're _kissing._

He's kissing _Stiles_ , and it feels so good, and so right, and because of that he thinks maybe he's still asleep, still dreaming.

It makes sense.

He has to be dreaming, so he just goes with it, opening up and licking at the seam of that mischievous mouth, imploring, possibly even begging for entrance. He's always wondered what it would feel like to do this, to kiss Stiles; but when those sweet lips part and a warm, smooth tongue slides up alongside his own he pulls away as though he's been physically burned, his foggy, sleep-addled brain finally kicking into full gear. He's pretty damn sure he's not dreaming. "We shouldn't be doing this," he gasps, carefully pushing Stiles off him as he sits up in the bed.

"No no no, come on," Stiles argues, voice thick with sleep, "Please don't stop. I need to feel this, Derek." He leans back in, hands coming up to cradle Derek's face, one on each side, pulling him closer. "Just once," he says, and he sounds fucking wrecked, "Just this once, with you. I _need_ this. Can you understand that? I—I need something real. Just this once...please, just...just once before I—before I...I—"

"Stiles," he breathes, grabbing Stiles' wrists and gently pulling his hands away, "Your vulnerable right now." And to himself he silently adds, _it wouldn't be 'just this once'_. If he gives in now, he doesn't know if he'll be able to stop. Doesn't know if he's strong enough to even try.

"Derek, I'm _dying._ "

And that word—fuck, that word feels like a punch to the gut, a serrated knife ripping his heart out, a bucket of ice water being poured down his spine.

"Do you honestly think I care about vulnerability right now?" Stiles continues, a small laugh bubbling up and out of him, "Because fuck that, okay? I don't care. I really don't. I told you, I need something I know is, is _real._ Something I can _feel._ And I wanna feel it with _you._ I don't wanna die a virgin...I, I wanna be with you, Derek..." he sighs, his lips quirking up ever so slightly, "I've...fuck, I've wanted you since the day we met out in the woods. You know that, right? You've gotta know that; you can hear my heartbeat. You know I'm telling the truth. So please, do this for me." He stops there, a look of uncertainty flitting across his face, his smirk dissolving right before Derek's eyes, "I mean, unless you, um, you don't—you don't want to? You don't want _me_. Unless you aren't..."

"Hey, shhh." Derek's finger comes up to press gently against Stiles' lips, halting his rambling, "That's not at all what this is about, okay?" He looks at him carefully, studying him. He wants this, too. He can't deny it. He's wanted this for so long, but Stiles is young. He's a _teenager._

He's too young.

But then, that's the thing now, isn't it?

That's the crux of it, the situation, their new reality.

Stiles is always going to be _too young_. Or _too sick_. Or _too different_. Once the symptoms of his illness truly hit, Stiles may not even _be_ Stiles anymore, and that thought...that thought terrifies Derek like nothing else, leaves a gnawing, gaping, cloying pit in his stomach.

So if Stiles wants to feel something real, then Derek will give him something real.

He can do that.

He'll give Stiles what he needs, what he _wants_ , and maybe he'll get the same thing in return...if only for a moment. If only _just this once_.

Maybe that's selfish.

Better yet, maybe that's fucking _illegal._

Maybe that makes him a terrible person.

He leans forward and meets their lips anyway, putting the troubling thoughts out of his mind.

Stiles feels soft and warm, new and exciting. There's a sweetness to him, sugary like candy; but there's also a slightly medical undertone dancing on those beautifully parted lips that Derek imagines has always been there to some degree. It's not a hindrance, it's just...there. It's chemical, a mixture of salts and stimulants, but it's all still purely _Stiles._ He deepens the kiss, chasing the taste as he delves into wet heat, mapping every contour he comes to. When their tongues slip together this time he doesn't pull away, and a moan escapes Stiles' throat, the sound of it spurring Derek on. He gently pushes Stiles back to lie on the bed, and his hips move of their own volition, grinding down into the inviting cradle of warm thighs curling around him. Sparks ignite deep in his core, pleasure thrumming through him as he feels the evidence of a clothed arousal, a hard and heavy line of heat, pushing against his own...and he _wants_.

God, Derek wants.

He wants _more._

He wants to make Stiles forget about everything else—everything outside of this room, outside of _them_ —and just be here, in this moment, together.

He lifts up and hooks his fingers below the hem of Stiles' shirt, pulling until it's over his head, then divests himself of his own as well before looking down to drink in the sight laid out before him. Moles litter Stiles' skin, a plethora of constellations covering the smooth, pale expanse of his chest and abdomen, soft and golden in the morning light.

Beautiful.

Stiles is fucking beautiful, and his scent has grown sweeter still, luring Derek in like a siren. He leans back over that warm skin and they kiss once, twice more; then he's breaking away, mouthing down along a sharp jaw to the creamy column of Stiles' neck, breathing in deep, scenting him, surrounding himself with the smell. He kisses Stiles' clavicle, then his chest—his tongue following every freckle and mole and beauty mark on his way. When he takes a nipple into his mouth, Stiles hisses, arching into the touch as blunt nails scratch across Derek's scalp. He nips and sucks the little pink nub, feeling it rapidly harden into a fine peak under his ministrations. Then his tongue laves at the reddened flesh, soothing the sting away before moving to the other side to lavish the same affections there.

He commits every curve and slope of skin to memory.

Every taste.

Every smell.

Every sweet sound that's drawn from Stiles' mouth.

He wants to remember it all, wants to make everything permanent.

When he reaches a warm navel, he fucks into it with his tongue; and Stiles instantly bucks his hips, his erection rubbing up against Derek's chest, kissing his bare skin through damp fabric. The titillating contact stops him in his tracks, and he pulls his mouth away as his hands come to rest on those greedy hips, a firm pressure keeping them still. His fingers curl around the elastic band of Stiles' sleep pants. "Are you sure?" he asks, voice raspy, throat tight.

He prays Stiles doesn't say no.

"Y-Yeah, Derek. Yeah, I want this. I wanna feel you _in_ me, _fucking_ me. Please...please, just, come on. Let me feel you."

He can't rein in the low growl that rumbles out of him at the declaration, breathy and erotic as it is, so he gives in and let's his wolf surge forward, pulling the flannel pants in his grip down with one quick sweep. Stiles' boxers follow after, black with a bright yellow Batman symbol across the crotch.

Again, he can't help the huff of amusement that escapes him at the sight.

"What?"

"Batman?" he smirks, "Really, Stiles?"

"Yeah, Derek, Batman," Stiles answers, looking massively affronted, "You got a problem with 'em, big guy?"

A warm heat settles in Derek's chest, affection and fondness. "No," he smiles, shaking his head, "No, not at all."

He hears a muttered reply of, "Damn straight," as he leans back down to kiss Stiles once more. Then, without breaking contact, Stiles is speaking against his lips, "Derek, I'm pretty sure you still have way too many clothes on if you're actually planning on fucking me."

His cock jerks at that, straining inside his too tight jeans, and he lifts up, humming in agreement. "You're right about that," he simpers, "Do you have any lube?"

"Well, _duh._ " Hazel eyes sparkle as Stiles smiles up at him. "Dude, I'm a seventeen year old male. 'Course I have lube." His gaze darts over to the side of the bed, "Nightstand drawer. Uh, under the Twizzlers and the Pop Rocks."

Derek quirks a brow at that, but gets up and pulls the drawer open just the same, searching through an impressive pile of junk food before coming away with a half full bottle of lube and an entire box of condoms—unopened. He shoots Stiles a questioning look.

"What? _Seventeen year old male_ , remember? I was prepared for...you know... _things_."

"Uh huh."

He opens up the box and takes one foil package out, then promptly shucks his jeans and boxers, letting the garments pool at his feet as cool air hits his filling cock. Before he realizes it, he's giving the hard flesh a quick jerk, melting into the touch of his fist; and he hears a strangled gasp from the bed. Stiles is practically devouring him with his eyes, those gorgeous eyes that look like copper in the morning light, glittering with mischief. They're so full of life, and Derek's heart aches just a little because of it.

He tries to shake away the somber mood as best he can, though, not allowing his mind to wallow there—that's not what this is about. This isn't about the possible sorrow looming on their horizon, it's about Stiles, and what he needs right _now._

So he climbs back onto the bed, his body blanketing Stiles' slighter frame as slender legs open to make room, and he fits perfectly in the space provided. Their lips brush, a touch that's already so painfully familiar to him, a touch Derek never wants to live without; and a rush of sensation washes over him when the velvety soft skin of their naked cocks meet for the first time. It's like an electric surge pulsing through the both of them, a powerful force, charging their movements and urging them on; and they each moan into the other's mouth, swallowing the rapturous sounds their movements evoke.

After a few minutes Derek pulls away again, moving back down the smooth line of Stiles' body, following the same path he took before until his tongue is lapping along the fine hairs leading to the one place where he knows Stiles' scent is the strongest. His hands find the lube he'd tossed on the bed and click the bottle open, squeezing a dollop of it onto his fingers while his breath ghosts over the engorged erection jutting up Stiles' abdomen, hard and red and angry. There's a sparkling pearl of fluid glistening at the tip like a crown, and his mouth waters with anticipation as it slowly begins to dribble down the shaft. He licks his lips, worrying the bottom one between his teeth while he lets a slick finger gently slide along the seam of Stiles' balls, then down to massage his perineum, and further still to tease at his entrance, circling the puckered hole.

"Der—Derek!" Stiles gasps, mewling and writhing under his touch, hands clenching white-knuckled in the sheets at his sides. "Please, _please!_ Jesus fuckin' _Christ_..."

"Shhh, I've got you," he soothes, "Just relax for me."

"Yeah...o-okay."

Carefully he presses one finger in, slow and steady, and Stiles' body eagerly accepts him as he leans down to nestle his nose into curly hair. The smell of sex is almost overwhelming right there, in the crook of Stiles' groin, the scent intoxicating in its absolute purity; and he inhales deep against the base of Stiles' cock, his own dick throbbing, leaking his desire copiously onto the sheets below.

He can feel his eyes burning with the need to shift to alpha red, can feel the tingle in his gums as his fangs itch to burst through, can feel claws trying to grow from the tips of his fingers.

Another growl emanates from the back of his throat with the effort it takes to hold the shift at bay, and Stiles spreads his legs wide in answer, opening himself up—offering his body to Derek to do with as he pleases. His wolf hums just beneath the surface of his skin, simmering, approval rolling off him in waves as he pulls his finger out of slick heat only to push it right back in again.

The whine Stiles emits at the action—all needy and frantic—purges any remaining control Derek has left, and he flattens his tongue against the underside of Stiles' cock, following the large vein there as he licks a long stripe up to the leaking head. A kaleidoscope of flavors flood his senses, sharp and sweet and bitter, and the combination of it all bombarding him at once sends a jolt of pleasure whirring through him, settling hot and heavy in his groin. His tongue flicks out to lave at another ample bead of precum sliding down the slit before swirling around the cockhead; then he's taking the entire length into his mouth, opening up his throat and swallowing it down to the hilt as he adds a second finger alongside the first.

Every thrust into Stiles pushes a muffled string of heady curses and moans out of him as Derek continues his ministrations, systematically taking him apart piece by piece with tongue and teeth and hands. He bobs up and down over the shaft, hollowing his cheeks with every ascent while he opens Stiles up, coating his insides in slick and thoroughly preparing him to take his alpha's cock.

Two fingers swiftly turn to three, and Stiles is groaning, his heart hammering, pounding hard against his ribs—so hard Derek can feel the pulse of it thumping heavily against his tongue. "Mother fuck..." Stiles' voice is strained, breathless as he rolls his hips up to fuck into Derek's mouth and down to fuck over his fingers.

Up and down, undulating and writhing, pleading for more.

 _Begging_ for it.

Derek gives it to him with a flick of his wrist and a crook of his hand, twisting _just right_...and Stiles' entire body jolts, trembling as he cries out, breathy and broken, skin slick, glistening with sweat, chest heaving as he gasps for air. "Der, fuck, that's...that's—oh god, right _there._ " He shudders, a full bodied tremor shooting through him as he loses the last vestiges of his self-control, "Oh my fucking _god._..."

Derek smirks, popping off his dick and pulling out of his ass, meeting his heavy gaze as Stiles whines in protest of the loss. "You like that, don't you?" he asks, voice a low growl, predatory, hungry. He's just barely managing to keep the wolf reined in. "You like feeling me inside you."

"Pretty sure that's a _hell yes_ , Obviouswolf," Stiles rasps, panting and arching his back, spreading his legs wider, "Fuck, I want you in me."

Those words send liquid heat dripping down his spine, trickling lower, filling his cock; and he snatches the condom up, tearing it open with his teeth. His eyes never leave Stiles', though, continuing to examine him, needing to make absolutely sure this is really what he wants. "You're _sure?"_ he asks, unable to keep the edge of desperation out of his tone.

"Oh my god, dude, yes! _So_ fucking sure, man. So sure...but, um..." Stiles stops, looking between Derek's eyes and his hands, nervously licking at his lips, Adam's apple bobbing as he swallows convulsively, "Do we, ah, really need the condom?" His cheeks turn a brilliant shade of red, embarrassment infusing the air, "I mean, it's just, um, I'm a virgin...and you, well, you know...you're all, like, wolfy and stuff, so..."

That gives Derek pause.

Technically no, they don't need a condom. He can't contract anything, and in turn, he can't give anything to anyone else; but it's still a big decision to choose not to use one. Not that he'd be opposed to going bare, of course. He's already established that his willpower is fucking shit when it comes to Stiles. "No," he shakes his head, "We don't really need one, but I want you to be comfortable with this."

"Oh I am!" Stiles vehemently nods, "I am, Derek. So comfy. Like, you have no idea, my dude. The levels of my comfyness would astound you. Truly, that's me...the epitome of relaxed, right here—"

"Stiles," he cuts him off, grinning, "Shut up."

"Oh—uh, okay. Shutting up now."

Derek tosses the opened condom to the side and instead slicks up his bare dick, giving it a few aborted tugs before leaning back over Stiles, aligning their bodies and meeting hazel eyes. Then he's pushing in, the head of his cock breaching that tight ring of muscle and slowly advancing as it gives way, yielding to his will.

"Fuck, Derek—" Stiles' breath hitches, his eyes clenching tightly shut and his brows furrowing as he groans his discomfort into the silence; and Derek instantly moves a hand down to grip around his hip, canting it up for better access while he siphons the pain from him.

Inky black bleeds into his veins, and soon Stiles relaxes, arching up to meet him, blunt nails digging into his shoulders for leverage. He doesn't stop pressing forward though, doesn't stop sliding in inch by agonizing inch—doesn't think he could even if he wanted to—not until he's fully sheathed in gloriously velvet heat, the tight channel surrounding him hugging him close, connecting them, tying them up together so completely that he wants to cry out in blessed relief.

Nothing else matters to him in that moment.

There are no obstacles keeping them apart.

No monsters or fears or illnesses hindering their union.

No threats of death looming over their heads.

There's nothing but two hearts beating a rapid staccato against one another, skin sliding across skin, warm breath mingling, sex and sweat and lust heavy in the air.

Nothing but Stiles, warm and all encompassing, filling him, overwhelming him, calming him.

He leans down, shaking, bracing his weight on his forearms as his nose nuzzles into the curve of Stiles' neck; and he breathes in deep, again and again, willing the sweet scent to linger, to become a permanent part of him—essential. "Stiles—" he chokes on the word, takes another intoxicating breath, "God, Stiles, you...you feel so good. Fucking amazing."

"Y-Yeah," Stiles stutters in response, the hum of his voice sending vibrations through his skin, seeping up into Derek's, "This is...fuck, this is good. So so good, Der..."

After that, nothing else is said. It's quiet, and they just tarry there, wrapped up in the other's arms, immersed in the moment, fingers exploring, mouths tasting. He counts every beat of Stiles' pulse against his lips as he kisses down his throat, lets himself relax into the rhythm of it as it begins to slow.

He has no idea how long they stay like that, locked in pleasurable stasis while they adjust, but he's brought back from the haze by long legs tightening around his waist and a low, tremulous voice whispering in his ear.

"Der, buddy, hey... _move_ already. I...I really need you to start moving. Like, right fucking now."

So that's what he does.

He lifts up and meets Stiles' heavy-lidded gaze, keeping those copper eyes fixed on his as he palms the soft flesh of Stiles' ass, pulling out almost completely. Cool air hits his cock, shocking him, and he pushes right back into warm pressure, savoring the exquisite feel of the greedy muscles stretching around him, drawing him in deeper. His movements are slow and gentle, careful, almost reverent as he cherishes the body splayed out before him. Arms wrap around his neck and pull him down into a kiss; then they're just staring at each other, connected from sternum to groin, skin on skin, panting, mouths mere inches apart. They rock together on the bed, bodies moving in perfect unity as they share air and space, pleasure and need.

Derek gets lost in the easy rhythm they set, the hypnotic swaying.

Sheets rustle below them.

The mattress creaks under the shared weight of their movements.

Nails scratch long lines down his back.

Teeth graze his jaw—nip along his chin, his neck, his ear.

The air around them is damp, saturated with the smell of sweat and musk, lust and longing.

Longing for something more. Something huge and important and _right there_. It's right in front of him. He can feel it simmering between their bodies, screaming at his wolf. It promises him things; dangerous things like love, and joy, and _mate._

Things like forever.

But that's something they may not have.

Not now.

Not ever.

Not anymore.

He tries not to dwell on that thought as he continues to grind down into the gorgeous body below him, plunging deeper with every pass, drawing little whimpers and moans and gasps from Stiles' mouth. That gorgeous fucking mouth.

Derek could devour that mouth.

He tries to, too, as his arousal morphs into something a bit more animalistic. Something wild and carnal—savage. He tongues his way into wet heat, and Stiles readily opens up for him, parting his lips and meeting him half way as they share sloppy, lazy kisses, each fucking the other's mouth in tandem.

His hips thrust forward, growing stronger, pounding home again and again.

Stiles is pliant through it all, the sharp scent of his own arousal rapidly peaking, sending Derek's senses into a feral frenzy to please—to make Stiles fall apart—to fucking _ruin_ him. He growls as his hand moves down to encircle the cock trapped between them, hot and hard, heavy and leaking; and he strokes the heated flesh in time with his hips.

The nails at his back dig in deeper as Stiles cries out.

"Come on," Derek softly rumbles, coaxing, licking a line up salty sweet skin, "I wanna feel you let go, Stiles. I wanna feel you give in to me. Just let go of everything and come for me, baby. Come for your _Alpha,_ my sweet boy..."

The command is instantly obeyed.

Derek feels Stiles' entire body go rigid against him, head flying back, baring his throat; and then he's coming with a strangled sob of Derek's name, tears falling down his temples as he bathes Derek's fist in hot, sticky release. The wolf in him purrs at the erotic sight of his boy, lying filthy and wanton beneath him...fucked out and panting, mouth hanging open, lips red and kiss-swollen, skin flushed and eyes dark like whiskey, shivering as he empties his seed across his own stomach.

The smell of it triggers a desire in him that has his gums itching again, his mouth watering. He wants to taste Stiles, wants to swallow him down, needs it more than fucking air. It's primal, and essential, and he can't hold it back so he doesn't even try. Instead, he leans in and lets his tongue trail through the spunk pooling on Stiles' skin, hungrily lapping it up. It's sharp and bitter, but there's a warmth to it, too—a mixture of spices filling out the profile that has Derek going back for more.

Stiles' body quivers under him.

All the while, the heat surrounding his cock grows stronger as muscles clench tight around him, pulsing and undulating through the final stages of orgasm; and he can feel his own climax mounting with every beat. He lifts back up as his hips begin to stutter, pleasure buzzing through him, flooding his nervous system like an atomic blast; and with one final massive thrust, he gives in.

"Stiles," he gasps, and the name sounds like a desperate, pleading prayer to his ears.

"Yeah," Stiles whispers in turn, pulling Derek's face down to meet the hollow of his bared throat, "My wolf..."

Warmth fills his chest at the name and the overt show of submission, sparking a burning fire of possessiveness in his heart, and all he can think is _mine mine mine._

He moves his mouth to the juncture between Stiles' neck and shoulder, biting just hard enough to bruise that beautifully pale skin...hard enough to mark him, to _claim_ him.

 _Mine_.

The moan that follows sends one final bolt of electric heat cascading down Derek's spine, filling his balls and pushing him over the edge.

He comes, _hard_ , his eyes glowing red and his teeth just shy of too sharp as his orgasm is ripped out of him in a blurred and blinding rush. It's like a tidal wave, massive and devastating, crashing over his mind again and again as his cock pulses hot and deep, spilling everything he has into the writhing body below. Ripples of ecstasy shimmer through every fiber of his being, heightening his senses; and he shudders as the remnants dissipate into the air around them, amplifying their connection.

Then they just lie there, breathing heavy, soaking up the other's presence while silently enduring the euphoric aftershocks. Their hearts beat in concert, slowly calming as they come down from the high of culmination.

After several minutes—or possibly hours, Derek really doesn't know—he finds the strength to pull out and settle beside Stiles, who merely protests the loss with a weak whimper, but nothing more. He grabs the first thing he sees, which just happens to be the Batman boxers, and does his best to clean them both up; and Stiles doesn't even complain, apparently still too blissed out and dazed to care. Then they're curling into one another without saying a word, and it feels so _right._

That's really the only term Derek can think of to describe how it feels to have Stiles in his arms.

Absolutely fucking _right_.

It feels like this is the way it's supposed to be—the way it's always been, even.

Derek and Stiles.

Together.

The two of them against the world.

"Don't go," Stiles murmurs, half asleep as his fingers lazily card through the hair at the nape of Derek's neck. The sensation sends goosebumps blossoming over his skin. "Please, don't go. Just stay here. Stay here with me, Der. Please..."

His arms tighten around the sleepy boy, _his_ boy—the boy who'd somehow, miraculously, in the blink of an eye, become the most important person in his life.

"Shhh. I'm not going anywhere," he whispers, running his hand along the curve of Stiles' spine, lingering at the small of his back as he tucks Stiles' head against his chest. "I'm not leaving you, okay? I'll never leave you, my sweet sweet boy, so just rest now. I'll be here when you wake up." He places a kiss to the top of Stiles' head, takes a deep breath, "I'll be right here, for as long as you need me."

"Yeah?"

"Yeah."

He feels tears start to well up in his eyes, and he finally lets them fall as the promise leaves his lips, realizing then and there that he means every single word.

He won't leave Stiles.

He'll be with him through it all.

Through everything that's coming.

He doesn't really know what the future holds for the two of them, together, or how it will look. He doesn't even know if they're going to _have_ a future. If Stiles decides against taking the Bite, there won't be much of a future _to_ have. He's not going to pressure him, though; that much he does know. No one should be forced to endure something that traumatic against their will, no matter the consequences—even if his wolf would like nothing more than to see those pretty hazel eyes glow beta gold.

He loves Stiles too much to do that to him.

 _Love_.

Yeah, okay.

So he loves Stiles.

He has no idea when _that_ became a thing...when it actually happened, or when he started to care so deeply for the kid lying in his arms. Maybe it was the moment he'd realized Stiles might be taken away from him.

It doesn't really matter, though.

Stiles is a part of his life now. He's a part of his pack, a part of _him._ In some ways, Derek feels like Stiles has always been a part of him...the boy who runs with wolves.

His lips curve up at the thought.

Stiles is in Derek's skin and bones, in his thoughts and fears, in his joy and his pain.

He's in Derek's heart— _is_ his heart.

He's Derek's constant in a world of ever changing flux, keeping him grounded, keeping him human.

He's right, and he's good, and he's perfect.

Stiles is Derek's anchor.

And he's permanent.

.

 _ **Will you think that you're all alone when no one's there to hold your hand?  
When all you know seems so far away and everything is temporary, rest your head.**_

 _ **I'm permanent.**_

.

 _ **-David Cook, 'Permanent'**_

.

Fin

.

* * *

 _Thank you all so much for reading. If you enjoyed it, let me know!  
_


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